The chromophore-protein complexes active as accessory pigments in the photosynthesis of the cryptomonad algae will be studied. Efforts will be made to isolate and characterize chlorophyll c or chlorophyll a/c proteins. Essentially nothing is known concerning the in vivo structure and function of chlorophyll c. A particularly important aspect of this research is to establish the various ways that the protein uses to modify the chromophore's spectroscopic properties. For allophycocyanin we found evidence that suggests the sepctroscopic properties are strongly influenced by chromophore-chromophore interaction, and that this interaction is controlled by the assembly of the protein. These concepts will be applied to the cryptomonad biliproteins, phycocyanin and phycoerythrin. Various types of biliprotein and various aggregates, dimers, monomers and subunits, will be compared by spectroscopic technics, including absorption, fluorescence, fluorescence polarization, circular dichroism and picosecod kinetics. It is our goal to establish the particular roles of chromophore interaction, solvation and conformation in the function of these pigments.